Restoring soil productivity
The Morton County, N.D., Soil Conservation District and Bismarck State College Farm Management Education received a Conservation Innovation Grant. The three year project studies the use of intensive cover crops with no-till farming to increase production on highly erodible, low-quality land.
This land had generally been in a one- or two-grass mix for 30 years or longer and produced at a very low rate. If grazed, it supported about 15 bred cows per year, and, if hayed, even on the years with high rainfall, produced well under 1 ton of hay per year. In farmer terminology, this is considered to be “land that should have never been broken.”
• Three-year project aims to restore the productivity of poor land.
• Researchers used cover crops to “wake up” the soil.
• A dramatic increase in forage production has been realized.
In early summer, the grasses were chemically killed with Roundup, and a mixture of cowpea, millet, radish, turnip, sunflower, sweet clover and soybean was seeded with 50 pounds of a starter fertilizer applied.
In most cases by year-end a vigorous stand of plants, averaging 24 to 30 inches tall, emerged. One unit in the project had cover crops a year earlier, and last year the crops stood 40 to 48 inches tall, while check strips continued to produce grasses from 8 to 12 inches in height. This particular unit has extremely light soil and is extremely fragile ground. It was very strange to see such strong production from ground that would normally have never been considered capable of this type of production.
The diverse mixture of crops helps to wake up the biology of the soil by increasing the number microorganisms, so that it can become much more productive. When examining the plants, you could see that the nutrients in the plant were adequate for good growth, even though only a small amount of starter fertilizer was applied. The soil biology was providing the nutrients for this excellent growth.
So far the project has provided several lessons.
• Spray out the grasses when they are actively growing to get a good kill. Where the grasses were not totally killed, the cover crops suffered severely.
• Seed the cover crops early enough to ensure adequate rainfall for good growth. Those seeded in June responded best.
• Get adequate growth before late summer’s typical decrease in rainfall and increase in heat. To maintain adequate cover for such fragile ground, the seeding must be done with a no-till drill.
Further articles over the next few years will outline the outcomes of the project.
Holkup is a farm business management instructor at Bismarck State College. Contact him at 701-224-5417 or Mark.Holkup@
BEFORE: The land was capable of producing about 1 ton of hay per year, or grazing for about 15 bred cows per year.
AFTER: The first year cover crops grew to be about 24 to 30 inches tall. The second year they grew to be 40 to 48 inches tall.
This article published in the April, 2011 edition of DAKOTA FARMER.
All rights reserved. Copyright Farm Progress Cos. 2011.